Efforts to reduce manufacturing costs of chemical products are on-going. Particular attention has been directed to reducing energy costs by implementing heat integration design, that is, the process-wide pairing of heat-releasing streams with heat-accepting streams. In addition, energy usage has been lowered by the adoption of more thermodynamically efficient design of unit processes such as distillation, heat exchange, and the like. It is also advantageous to reduce the production of liquid waste streams to lessen incineration or other disposal costs which are imposed by ever-increasing environmental concerns.
In methanol production, fusel oil comprising primarily aqueous methanol and other volatile organic reaction by-products is a primary liquid waste stream. It has been known to recycle the crude, untreated fusel oil stream to the reformer feed, either directly to the reformer inlet coils or by means of a feed gas saturator on the reformer hydrocarbon gas feed. This has the potential for damaging the reforming catalyst if the fusel oil contains any solids such as methanol synthesis catalyst particles, caustic or other components carried over from the methanol synthesis that can damage the reforming catalyst. More commonly, fusel oil waste streams have been burned as fuel to heat a reformer. However, recent environmental thinking regards fusel oil as a hazardous material unsuitable for incineration, and has potentially increased the cost and complexity of fusel oil disposal. Thus, it would be beneficial to recover the methanol and other reaction by-products from these fusel oil waste streams to concurrently enhance product yield and eliminate these liquid waste streams, and thus address these environmental concerns.